Geological Survey Professional Paper 294—D Stromatolites of the Belt Series in Glacier National Park and Vicinity, Montana

Genus CRYPTOZOON Hall, 1883

Cryptozoon Hall, 1883, N. Y. State Mus. Ann. Rept. 36, pl. 6.

Genotype: Cryptozoon proliferum Hall, 1883.

Generic diagnosis.—Colonies begin growth from a point on the substratum and grow upward by the addition of convex upward laminae. Gross form is depressed hemispheroidal or turbinate.

Cryptozoon occidentale Dawson (emend. Rezak)
Plate 20, figure 5; plate 21, figures 1, 2, 3

Cryptozoon occidentale Dawson, 1897, Canadian Rec. Sci., v. 7, p. 208, fig. 3.

Cryptozoon? occidentale Dawson. Walcott, 1899, Geol. Soc. America Bull., v. 10, p. 233, pl. 23.

Collenia occidentale (Dawson). Walcott, 1914, Smithsonian Misc. Coll., v. 64, p. 111, pl. 15, figs. 1-6.

Collenia compacta Walcott, 1914, Smithsonian Misc. Coll., v. 64, p. 112, pl. 15, fig. 7.

Fenton and Fenton, 1931, Jour. Geology, v. 39, p. 684, pl. 8, fig. 2.

Specific diagnosis.—Colonies subcircular in plan; fan-shaped in cross section, range in height from a few inches to 6 feet; maximum width about equal to height. Laminae smooth; dome-shaped in younger parts becoming flattened at crest and incurved around margins as colony grows larger. Each lamina slightly larger than preceding one, giving rise to fan-shaped cross section.

Syntypes.—USNM 60710, 60711.

Type site.—Grand Canyon, Ariz.

Occurrence.—Chuar group, Grand Canyon region; upper Grinnell argillite, upper Siyeh limestone, and occasionally in argillites of the Missoula group.

Remarks.—Walcott (1899, p. 233) was obviously undecided as to whether C. occidentale should be included in Collenia or Cryptozoon. Later (1914, p. 111), he transferred the species to the genus Collenia, explaining that Cryptozoon occidentale grew much in the same way as Collenia undosa "except that owing to its being crowded together it grew to a greater height from a narrow base." He did not mention that the colonies were not crowded until after they had attained considerable height. Because of the fact that C. occidentale began its growth from a point on the substratum, it is here referred to the genus Cryptozoon. Walcott (1914, p. 111) also remarked on the resemblance of Collenia compacta to C. occidentale, the only difference being that C. compacta developed laminated growths between the club-shaped individuals. Laminated growths between individual colonies are quite common in fossil stromatolites and are not here regarded as specific characteristics. Actually, the holotype of C. compacta does not show the entire structure of the colony. In examining Walcott's specimens and later collections, the structure described in the specific diagnosis is readily seen.

Genus COLLENIA Walcott, 1914

Cryptozoon Hall. Walcott, 1906, Geol. Soc. America Bull., v. 17, pl. 11.

Collenia Walcott, 1914, Smithsonian Misc. Coll., v. 64, p. 110.

Genotype: Collenia undosa Walcott, 1914.

Generic diagnosis.—Colonies begin as incrustations on a surface of the substratum and grow upward by addition of convex upward laminae. Gross form cylindroidal or hemispheroidal.

Collenia undosa Walcott
Plate 21, figures 4, 5, 7, 8

Collenia undosa Walcott, 1914, Smithsonian Misc. Coll., v. 64, p. 113, pl. 13, figs. 1, 2; pl. 14, figs. 1, 2.

Fenton and Fenton, 1931, Jour. Geology, v. 39, p. 684, pl. 6, pl. 7, figs. 3, 5.

Fenton and Fenton, 1937, Geol. Soc. America Bull., v. 48, p. 1947, pl. 11, figs. 3, 4; pl. 14, fig. 3.

Collenia willisii Fenton and Fenton, 1937 [in part], Geol. Soc. America Bull., v. 48, p. 1945, pl. 11, fig. 1; pl. 12, figs. 4, 5, 6.

Specific diagnostic.—Colonies expand upward to form hemispheroidal bodies. Sizes range from 1 inch in height and 2 inches in diameter to 18 inches in height and 20 inches in diameter. Laminae coarsely crenulate and rather strongly convex upward. Colonies expand upward with growth and unite laterally with others to form biostromes with striking mammillate surfaces.

Holotype.—USNM 60707.

Type site.—Eight miles west of White Sulphur Springs, at forks of Birch Creek, Meagher County, Mont.

Occurrence.—Spokane shales near White Sulphur Springs, Mont.; Grinnell argillite and lower Missoula group in Glacier National Park.

Remarks.—In examining the holotype of Collenia willisii Fenton and Fenton, 1931 (PUM 24020), I found it to be a part of a colony of Collenia undosa Walcott, 1914. Other members of the species C. willisii are here referred to Collenia multiflabella n. sp.

Collenia frequens Walcott
Plate 20, figures 1, 2, 3, 4, 6, 8, 9, 10, 11

Cryptozoon frequens Walcott, 1906, Geol. Soc. America Bull., v. 17, pl. 11.

Collenia? frequens (Walcott). Walcott, 1914, Smithsonian Misc. Coll., v. 64, p. 113, pl. 10, fig. 3.

Collenia columnaris Fenton and Fenton, 1931, Jour. Geology, v. 39, p. 682, pl. 1-2.

Fenton and Fenton, 1937, Geol. Soc. America Bull., v. 48, p. 1941; pl. 9, figs. 1, 2.

Collenia versiformis Fenton and Fenton, 1937, Geol. Soc America Bull., v. 48, p. 1947, pl. 14, fig. 2; pl. 16, fig. 4; pl. 18, figs. 1 and 2.

Collenia albertensis Fenton and Fenton, 1937, Geol. Soc. America Bull., v. 48, p. 1942, pl. 11, fig. 2.

Collenia expansa Fenton and Fenton, 1937, Geol. Soc. America Bull., v. 48, p. 1948, pl. 16, fig. 1, 3.

Specific diagnosis.—Widely spaced to closely crowded cylindroidal colonies that stand at angles of 50° to nearly 90° to bedding surfaces. Colonies from 2 inches to 15 inches in diameter and from 6 inches to 23 feet in height. Laminae smooth, strongly convex to flattened, not normally weathered into strong relief.

Type.—USGS a117 (by subsequent designation).

Type site.—Railroad cut along Bear Creek opposite mouth of Devil Creek.

Occurrence.—Altyn limestone, Siyeh limestone, and limestone lenses in the Missoula group.

Remarks.—Walcott published the species C. frequens in 1906, using a photograph without a description. The photograph was taken by Bailey Willis in 1901, and his caption reads: "Rock mass showing large concretionary or coralline masses in the Siyeh formation about 500 feet from the top of the formation. Head of McDonald Creek. Ridge between McDonald and Logging Creeks near the summit." Walcott, however, made no mention in his original paper of the site where the photograph had been taken. Later, (1914, p. 113) he gave the locality as "Little Kootna Creek (Waterton River), Chief Mountain Quadrangle, Montana." During the 1953 field season, an unsuccessful attempt was made to find the type site. In the general area of the site described by Willis, the Conophyton zone 1 was found to occur about 500 feet below the top of the Siyeh limestone. Subzone A of this zone contains well-developed cylindroidal colonies. Walcott's original illustration and later description of this species indicates without a doubt that the colonies assumed a cylindroidal form at right angles to the bedding surfaces. The Fentons describe C. frequens as being conical in form, mistaking it for Conophyton Maslov which is so abundant in the zone.

Collenia multiflabella n. sp.
Plate 21, figure 6; plate 22, figure 1

Collenia willisii Fenton and Fenton, 1937 [in part], Geol. Soc. America Bull., v. 48, p. 1945; pl. 10, figs. 1 and 3.

Specific diagnosis.—Colonies roughly circular in plan, hemispheroidal, range up to 3 feet in height and 5 feet in diameter. Laminae finely crenulate, flattened at crest, give appearance of fine mammillae on upper surfaces of colonies. Basal part consists of variable number of cylindroids expanding upward and capped by later laminae that are continuous over the columns. Slight downflexing on the laminae at the margins of the colonies.

Holotype.—USGS a118.

Type site.—Logan Pass, Glacier National Park, Mont.

Occurrence.—Collenia multiflabella zone in the upper Siyeh limestone.

Remarks.—The specific name refers to the expanding cylindroids in the basal part of the colonies. In natural vertical sections the cylindroids have a fanlike appearance. The Fentons have mistaken representatives of this species for Collenia undosa Walcott, The holotype and some of the paratypes of Collenia willisii Fenton and Fenton were collected from float near Iceberg Lake, and are believed to have weathered out of the Collenia undosa zone 2 some distance above their zone of Collenia willisii, and here are referred to the species C. undosa.

The reference to plate 13, figure 1, under the species Collenia willisii Fenton and Fenton (1937, p. 1945) is incorrect. The explanation of plates identifies the figure as Collenia clappii n. sp., which is here regarded as a subjective synonym of Collenia symmetrica Fenton and Fenton.

Collenia symmetrica Fenton and Fenton
Plate 22, figures 3, 4, 5, 6, 7, 8

Collenia symmetrica Fenton and Fenton, 1931, Jour. Geology, v. 39, p. 683, pl. 3-5.

Fenton and Fenton, 1937, Geol. Soc. America Bull., v. 48, p. 1942, pl. 10, fig. 2; pl. 13, fig. 1.

Collenia clappii Fenton and Fenton, 1937, Geol. Soc. America Bull., v. 48, p. 1948, pl. 14, fig. 1.

Collenia parva Fenton and Fenton, 1937, Geol. Soc. America Bull., v. 48, p. 1948, pl. 14, fig. 4.

Specific diagnosis.—Colonies 1 inch to approximately 20 feet in diameter and one-half inch to 10 feet in height; depressed hemispheroidal; subcircular in plan. Laminae smooth to finely crenulate, flattened centrally but sharply downfolded at margins of colony.

Holotype.—UCM 7703.

Type site.—Cut Bank Pass, Glacier National Park, Mont.

Occurrence.—Grinnell argillite, Siyeh limestone, and Missoula group.

Remarks.—C. symmetrica seems to have developed on newly submerged mud flats. It is ordinarily found upon a mud-cracked surface, and large amounts of associated breccia indicate agitation of the surrounding water. The only difference between C. symmetrica, C. clappii Fenton and Fenton, and C. parva Fenton and Fenton is in dimensions. The Fentons do not include dimensions in their description of C. symmetrica. However, they state that C. parva ranges from 12 to 17 millimeters in diameter and C. clappii from 5 to 105 centimeters in diameter. Size is here considered not to be a specific characteristic, and the three forms are regarded as the same.

Genus NEWLANDIA Walcott, 1914

Newlandia Walcott, 1914, Smithsonian Misc. Coll., v. 64, p. 104.

Genotype: Newlandia frondosa Walcott, 1914.

Generic diagnosis.—Incrusting colonies that grew upwards from a surface on the substratum by addition of concave upward laminae.

Newlandia lamellosa Walcott
Plate 23, figure 8

Newlandia lamellosa Walcott, 1914, Smithsonian Misc. Coll., v. 64, p. 106; pl. 10, figs. 1, 2.

Specific diagnosis.—Bowl-shaped to cup-shaped colonies from 1 inch to approximately 15 inches wide and from 1 to 10 inches high. Laminae smooth, concave upward; less concave than lower surface of colony.

Holotype.—USNM 60702.

Type site.—At forks of Little Birch Creek, about 8 miles west of White Sulphur Springs, Mont.

Occurrence.—Newland limestone at type site, possibly Grinnell argillite in Glacier National Park region and Burke formation in Coeur d'Alene district, Idaho.

Remarks.—The original description of the genotype N. frondosa and the fragmentary nature of the specimens used to illustrate the form give very little information on the mode of growth of this genus. Only by comparing my specimens with those classified by Walcott as N. lamellosa did the mode of growth and the gross form of Newlandia become apparent. Walcott described his species of Newlandia as "frond-like." The term is misleading because Newlandia, like Collenia and Cryptozoon, is an incrusting form and not frond-like.

Specimens collected in Glacier National Park and the Coeur d'Alene district have been doubtfully referred to this genus. The form is somewhat similar to the form of Newlandia, but the laminae are much more strongly concave and seem to parallel the lower surface of the stromatolite. (See pl. 23, fig. 7.) Some of these specimens are associated with probable slump structures, which makes their organic origin doubtful.

Genus CONOPHYTON Maslov, 1937

Conophyton Maslov, 1937b, Moscow Univ. Lab. Paleontology Pub., Problems of paleontology, v. 2-3, p. 344, pl. 4, figs. 2, 3.

Genotype: Conophyton lituus Maslov, 1937.

Generic diagnosis.—Cylindroidal colonies composed of nested conical laminae. Apex of basal cone usually attached to substratum; long axis of cone inclined at some angle to bedding surfaces.

Remarks.—Similar structures have been reported in the Otavi Mountains of South Africa (Schwellnus and le Roex, 1945). These, however, are vertically disposed with reference to the bedding and always point downward. R. B. Young (1940, p. 17-21) described conical structures in the limestones of the Dolomite series in the Transvaal. These are in the form of inverted cones similar to those in the Otavi system. V. P. Maslov (1937b, p. 344) described conical forms in the lower and middle Cambrian of the Aldan river and western Baikal regions, U. S. S. R., in which the apices are directed upwards. Maslov (1938, p. 380) later referred to forms reported by V. N. Makhayev from the Maia river region—forms that grow with the apex pointing downward and commonly are perpendicular to the bedding but may be inclined. It seems reasonable to assume from the field evidence in northwestern Montana and the descriptions of occurrences in South Africa and the U. S. S. R. that the colonies grew with the apices of the cones attached to the sea bottom. The significance of the anomalous orientation of the apices of the Aldan river material is not known at this time. Maslov did not mention his concept of the mode of growth in his original diagnosis. However, the strong resemblance between his illustrations of Conophyton and the material from the Belt series seems sufficient to allow the use of the name Conophyton for these specimens.

Conophyton inclinatum n. sp.
Plate 23, figures 1, 3, 5, 6, 9

Collenia? frequens Walcott. Fenton and Fenton, 1931, Jour. Geology, v. 39, p. 685, pl. 8, fig. 1.

Fenton and Fenton, 1938, Geol. Soc. America Bull., v. 44, p. 1135-1142, fig. 2, pl. 57.

Fenton and Fenton, 1937, Geol. Soc. America Bull., v. 48, p. 1946, pl. 15, figs. 1, 2.

Specific diagnosis.—Cylindroidal colonies consist of array of nested cones; inclined at low angles to bedding surfaces. Apical angle averages about 40°. Diameters range from 2 inches to 48 inches and average about 8 inches. Lengths up to 3 feet, but some may be greater. Laminae conical, concentric, and smooth.

Syntypes.—USGS a2, a283, a284.

Type site.—Just west of snowshed 6, Great Northern Railway, opposite the point where Devil Creek flows into Bear Creek, Glacier National Park, Mont.

Occurrence.—Conophyton zone 1 in the Siyeh limestone and the Conophyton zone 2 in the Missoula group. Conophyton does not occur outside these two zones in the area described in this report.

Remarks.—The specific name was selected because of the inclined position of the cones with reference to the bedding surfaces. Conophyton lituus Maslov differs from Conophyton inclinatum n. sp. in the position of the apex of the cone. In Conophyton lituus Maslov, the apex points upwards. Maslov mentions (1937b, p. 344) that Conophyton lituus occurs with Collenia in the Lower and Middle Cambrian of the U. S. S. R. It is therefore assumed that the stromatolite occurs in a normal sequence of strata and the anomalous orientation of its apex is not due to an overturned sequence of beds.